1. Field of the Invention
This invention relates to a method of cleaning a floppy disk for clearing the floppy disk of dust adhering to the surface thereof in the manufacturing process thereof and a system for carrying out the method.
2. Description of the Prior Art
There has been known a floppy disk which is a flexible magnetic disk accommodated in a flat casing. The casing has a head insertion opening which gives access to the magnetic disk to the magnetic head of a recording and reproducing system. Dust can enter the casing through the head insertion opening and adhere to the surface of the disk. A liner typically made of nonwoven fabric is provided on the inner wall surface of the casing in order to wipe the dust from the surface of the disk while the disk is driven.
During assembly of the floppy disk, dust is produced due to various mechanical impacts. Especially, when upper and lower casing halves are welded together by an ultrasonic welding, the liner is vibrated by ultrasonic waves and a large amount of fine particles of components of the liner falls on the disk surface and adhere thereto as dust. Further dust wiped from the disk surface accumulates on the liner to a large amount and can fall on the disk surface when the casing is vibrated. When the floppy disk is loaded in the recording and reproducing system in such a state, a part of the dust can be trapped between the disk surface and the magnetic head and so-called drop out can occur.
It has been proposed to remove dust in the casing by sucking air in the casing through the head insertion opening while rotating the disk in the cleaning step of the manufacturing process, as disclosed in Japanese Unexamined Patent Publication Nos. 62(1987)-270087, and 63(1988)-64685, and the like.
However, the dust generated from the liner due to the ultrasonic welding is charged due to intense vibration and firmly adhere to the outer surface of the liner, the inner wall surface of the casing and the disk surface near the head insertion opening. It takes a long time to remove the charged dust by the air sucking, and accordingly, the manufacturing efficiency deteriorates.